Technical Field
The present invention generally relates to vacuum transistors, and more particularly to transistors having a piezoelectric material for adjusting a vacuum gap between source and drain regions.
Description of the Related Art
Vacuum transistors have properties that can be advantageous in many instances. Also referred to as vacuum-channel transistors, vacuum transistors can operate at higher speeds than ordinary silicon transistors and can be more tolerant of heat and radiation. Electrons propagate freely through a vacuum, whereas crystal-lattice scattering occurs in solid state channels. In addition, vacuum is not prone to the kind of radiation damage that plagues semiconductors, and produces less noise and distortion than solid-state materials.
However, unlike the conventional metal oxide semiconductor field effect transistors (MOSFETs), vacuum transistors rely on direct electron tunneling from emitter (E) to collector (C). In conventional vacuum transistors, a back gate is used to modulate the electric field between emitter and collector. The advantages of semiconductors, which include lower costs, smaller size, superior lifetime, efficiency, ruggedness, reliability, etc. have outweighed the use of vacuum transistors in many applications.